Reports of a potentially critical Snow Leopard bug that can erase a user's account data have continued to surface since the operating system's debut [Updated with Apple official comment].

Since Mac OS X 10.6 launched in late August, numerous reports online have detailed the issue, which is triggered by logging in and out of a guest account on a Snow Leopard machine. Upon logging back in to their regular account, users will find that it has been wiped of all data.

The issue has prompted numerous threads (1, 2, 3, 4, 5) on the Apple Support Discussions, with reports suggesting the issue cannot be reproduced with any exact certainty. Apple has yet to publicly acknowledge the issue.

"When I logged into my MacBook Pro this morning, it was as if I had logged into my Guest Account and not my standard user profile," user parshallnet said. "No icons on the desktop, the desktop wallpaper was the default 'space' photo and not the one I had assigned, no documents in the docs folder, apps behaved as if I'd never opened them before."

The issue was initially reported when Snow Leopard first launched, but complaints have grown as adoption of the platform has continued. Monday, Engadget highlighted the issue.

A month ago, CNet detailed a potential fix for the issue, which is reportedly caused when users have had a guest account enabled for login prior to the install of Snow Leopard. The easiest way to avoid the issue is disabling the guest account.

If afflicted by the bug, the home folder can be restored, though without a backup, the loss of data is likely permanent. If a user has Time Machine running, they can restore their Snow Leopard installation while holding 'C' at startup and choosing "Restore from Backup" from the "Utilities" menu.

Update: In a brief statement, Apple acknowledged the issue Monday evening, according to CNet

"We are aware of the issue, which occurs only in extremely rare cases, and we are working on a fix," a spokesperson said in a prepared statement.

Since its launch in August, Snow Leopard has been received with positive reviews and strong sales. A quick update, Mac OS X 10.6.1, was released soon after, but apparently did not provide relief from the guest account bug.

Mac OS X 10.6.2 is currently in beta and only available to developers. It has nearly 150 general focus areas.

I'm glad I never ever use the guest account, but this needs to be fixed yesterday.

The problem seems to be related to guest accounts carried from Leopard to Snow Leopard. As far as I know, if you enabled your guest account under Snow Leopard or you disable then enable your upgraded snow leopard guest account then you will be fine. Furthermore, not every one had the problem and many were not able to reproduce the problem.

The problem seems to be related to guest accounts carried from Leopard to Snow Leopard. As far as I know, if you enabled your guest account under Snow Leopard or you disable then enable your upgraded snow leopard guest account then you will be fine. Furthermore, not every one had the problem and many were not able to reproduce the problem

that last bit seems to be the crux of the problem. they can't reproduce the issue to figure out what's wrong.

some folks are saying if you just have guest enabled it happens. others are saying you have to go into the guest account and afterwards, the next time you log into your regular account, everything is wiped out. Some are saying if you turn on guest in Snow Leopard, it happens. others say only if you had it on before you upgraded.

plus yet again, it seems that folks are hip to scream on the blogs but not to actually go to official Apple channels to give them the info they might need to figure out what's going on so they can fix it

that last bit seems to be the crux of the problem. they can't reproduce the issue to figure out what's wrong.

some folks are saying if you just have guest enabled it happens. others are saying you have to go into the guest account and afterwards, the next time you log into your regular account, everything is wiped out. Some are saying if you turn on guest in Snow Leopard, it happens. others say only if you had it on before you upgraded.

plus yet again, it seems that folks are hip to scream on the blogs but not to actually go to official Apple channels to give them the info they might need to figure out what's going on so they can fix it

Yes.. and this issue mysteriously just surfaced more than one month after Snow Leopard release. I follow few Apple centric websites and this is the first time I've heard about it!

Yes.. and this issue mysteriously just surfaced more than one month after Snow Leopard release. I follow few Apple centric websites and this is the first time I've heard about it!

Well, if it is related to upgrade installs, then the delay in major reporting isn't unexpected. The early adopters of Snow Leopard are probably on average more tech savvy and more likely to do a clean install which would avoid this problem. I believe Snow Leopard now defaults to upgrade and clean install is hidden, so as more people switch and just use the default upgrade install, more cases would crop up. If Apple is pointing everyone to use an upgrade install, they should have more thoroughly tested the common cases, which having a Guest account would seem to be.

And odd issue, quite uncharacteristic of Apple. An interesting "bug" that seems not easily reproducible, cropping up over a month after SL's release.

In any event, using the Guest account is extremely rare. You probably wouldn't find anyone doing beta testing on such an account. Whatever was changed in the code for that function was probably believed insignificant, so it wasn't thoroughly tested.

The Apple support thread contains around 50 posts, most of which aren't from people with this problem, who claim an occasional issue with something that only occurs in a particular method, sometimes but not always. This bug in Snow Leopard is apparently not easy to reproduce and will not even work on a clean install. So if you were planning on buying a new Mac, this wouldn't even affect you.

It helps to maintain the proper perspective on the issue. But with Apple, 10 users complaining = 10,000 users complaining. Everything is magnified, often irrespective of the actual breadth and scope of ths issue.

If you are using Snow Leopard and are NOT using Time Machine, I'm not sure what advice I could give.

If SL users aren't using Time Machine for some reason, that's fine. But they sure should be backing up by some method. At the very least, they should have a backup that they performed just before they did their upgrade to Snow Leopard.
But this does suck. Personally, I still have not upgraded to SL, and I certainly won't be until I know this bug is squashed.

Given that there are a significant amount of people with the Time Capsule failure issue as well though it would certainly suck to be in the group that overlaps with this issue. The Time Capsule failure has eliminated my backups without warning, if I also had guest users enabled under Leopard (which I did at one point), I would be in the position of losing everything even though I would be following all Apple advice and using all their latest software and hardware.

Personally, I think this is just one more indication of how over-stretched Apple is right now and how they really need to beef up their QC efforts to match the beefed up sales they've been enjoying.

I liked it better when Apple was a small company that no one else I knew had heard of.

It seems this problem does not happen on Snow Leopard (upgraded from Leopard) upon enabling guest log-in, which suggests one possibility could be some Snow Leopard incompatibility with how the guest log-in was initially enabled. If you had it enabled in Leopard before upgrading and the problem happened without any changes to the guest account settings, then it could be from an incompatible setting between how Leopard and Snow Leopard handle the guest accounts. As such, try going to the Accounts system preferences and toggling the guest log-in setting to see if that refreshes the way the system is handling the guest account.

Well, if it is related to upgrade installs, then the delay in major reporting isn't unexpected. The early adopters of Snow Leopard are probably on average more tech savvy and more likely to do a clean install which would avoid this problem. I believe Snow Leopard now defaults to upgrade and clean install is hidden, so as more people switch and just use the default upgrade install, more cases would crop up. If Apple is pointing everyone to use an upgrade install, they should have more thoroughly tested the common cases, which having a Guest account would seem to be.

Upgrade has always been the default installation for OSX, and the one I'd suspect is done by well over 90% of users. The "clean install" is mythical really, since no such option actually exists. If we're talking about "erase and install" this is a full geek option, not to be taken lightly or used routinely.

Anyway, this bug appears to be isolated. It's apparently not reproducible. Not that this is good, or makes it any easier to find, but it certainly does not seem to afflict many people.

Given that there are a significant amount of people with the Time Capsule failure issue as well though it would certainly suck to be in the group that overlaps with this issue. The Time Capsule failure has eliminated my backups without warning, if I also had guest users enabled under Leopard (which I did at one point), I would be in the position of losing everything even though I would be following all Apple advice and using all their latest software and hardware.

Personally, I think this is just one more indication of how over-stretched Apple is right now and how they really need to beef up their QC efforts to match the beefed up sales they've been enjoying.

I liked it better when Apple was a small company that no one else I knew had heard of.

Well, if it is related to upgrade installs, then the delay in major reporting isn't unexpected. The early adopters of Snow Leopard are probably on average more tech savvy and more likely to do a clean install which would avoid this problem. I believe Snow Leopard now defaults to upgrade and clean install is hidden, so as more people switch and just use the default upgrade install, more cases would crop up. If Apple is pointing everyone to use an upgrade install, they should have more thoroughly tested the common cases, which having a Guest account would seem to be.

Well. I don't recall knowing any average user who enables guest account. I always tell my average PC/Mac users family and friends to never mess with the guest account for security reasons. Furthermore, more than 3 millions bought SL within the first week or so and it doesn't make sense that just now these reports started popping up. I am not say the issue does not exist, I am saying the reports are over exaggerated because of yesterday report about MS/Danger data loss.

Personally this is my 2nd Mac (MBP) and I did an upgrade from Leopard, which was upgraded from Tiger on my iMac before migrating to my current MBP, without any problems what so ever. However, I've seen how other people use their PCs and Macs and I am not surprised that some are having issues during upgrades. But seriously, anyone who upgrade his/her OS without backing up first is to blame for any loss of data.

Well. I don't recall knowing any average user who enables guest account. I always tell my average PC/Mac users family and friends to never mess with the guest account for security reasons.

There are security reasons why you should use the Guest account for family and friends.

I have people over to my house all the time. They may want to "just check email" or "get map directions" etc... If they're in my account, well, then they have access to everything...not good.

One option is to set up an account specific to them, but that requires a bit of setup that could be awkward..."I don't trust you, so let me set up an account for you". It's a lot easier to just tell them to log in as Guest...and it may be easier for them too, because they may not have to log out of whatever your browser was logged into first.

I have one Mac that any number of people who come to visit may want to use...sometimes when I'm not there. Thus, setting up individual accounts isn't really an option.

The bigger issue, and reason for setting up a Guest account is that you're also protecting the guest. When the guest logs out, everything is wiped. This means they don't have to worry about you having access to anything, or another guest having access.

In a reception area in an office, this is a big deal too. You can set Guest to log-out after a time period, and not worry about their info being accessed if they forgot to log out of email or whatever.

The Guest account is a very useful feature...although not nearly as useful as Time Machine

There are security reasons why you should use the Guest account for family and friends.
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The Guest account is a very useful feature...although not nearly as useful as Time Machine

Agreed — on both counts. I too have a Guest account enabled, and for exactly the same reasons as you. However I doubt that many people do. In my observation the average Mac user seems to be largely unaware of the multi-user option or how/why to use it. That may explain why this bug, assuming it exists as described, isn't an epidemic.

Back in Leopard I had a similar thing happen. I switched accounts and when I came back my user account was done. After a log out or restart it was all back where it was before, but it did have the appearance of being gone for a moment. I recall it being a bit unsettling.

Quote:

Originally Posted by NasserAE

Well. I don't recall knowing any average user who enables guest account. I always tell my average PC/Mac users family and friends to never mess with the guest account for security reasons.

I agree with the other posters. Instead of having my Admin or user account accessible to people from a lack of password protecting or from logging in so they can use my machine, I have the guest account setup for friends/family as a secure option for guests.

Dick Applebaum on whether the iPad is a personal computer: "BTW, I am posting this from my iPad pc while sitting on the throne... personal enough for you?"

Well don't hold your breath, they rarely acknowledge anything. Even when they do, the Genius Bar will feign ignorance.

Sorry for the rant, but I just took my wife's MacBook in to the SoHo store in NYC, it has the flickering screen issue (for the 3rd time) and a cracked case (where the magnets connect). BOTH are well known and documented issues. Their diagnosis? It is 'accidental damage' and they're looking to charge $300+ to fix both, plus taxes.

I've got the MacBooks (a pair of them), ATV, 3GS, $3000+ on iTunes since 2005... this loyalty thing only seems to work one way. I am very frustrated and falling out of love rapidly.

I simply use my default account and don't require a password to log in. I was going to set that up and give my family their own to log in, but now I'll hold off a bit for fear this bug will surface.

As soon as I saw this issue I backed-up via TimeMachine. I don't have a TimeCapsule (I hear there's issues with those) so my MacBook isn't wirelessly tethered to my external hard disk. I take weekly backups at best which is good enough for me.

I simply use my default account and don't require a password to log in. I was going to set that up and give my family their own to log in, but now I'll hold off a bit for fear this bug will surface.

As soon as I saw this issue I backed-up via TimeMachine. I don't have a TimeCapsule (I hear there's issues with those) so my MacBook isn't wirelessly tethered to my external hard disk. I take weekly backups at best which is good enough for me.

Id imagine if its not yet, it will be by the time 10.6.2 gets finalized. But none of that should affect you. Youve got a TM back up and you setting it up after the installation of SL. At any rate, you can password protect your admin account and just create a non-admin account with no password that you deem the guest account. Even use parental controls to limit what it can do.

Dick Applebaum on whether the iPad is a personal computer: "BTW, I am posting this from my iPad pc while sitting on the throne... personal enough for you?"

I simply use my default account and don't require a password to log in. I was going to set that up and give my family their own to log in, but now I'll hold off a bit for fear this bug will surface.

As soon as I saw this issue I backed-up via TimeMachine. I don't have a TimeCapsule (I hear there's issues with those) so my MacBook isn't wirelessly tethered to my external hard disk. I take weekly backups at best which is good enough for me.

Time Capsule is fine, but if you already have a wireless-n router and only one Mac, you'd do just as well to buy an external drive for Time Machine. But If you need a wireless-n router and have more than one Mac, Time Capsule is a very nice solution.

Maybe someone can explain the advantage of using the guest account feature over creating a non-adminstrator's account manually. Off hand, I don't see it.

Time Capsule is fine, but if you already have a wireless-n router and only one Mac, you'd do just as well to buy an external drive for Time Machine. But If you need a wireless-n router and have more than one Mac, Time Capsule is a very nice solution.

Maybe someone can explain the advantage of using the guest account feature over creating a non-adminstrator's account manually. Off hand, I don't see it.

The Guest account deletes all files and history when it's logged off. This makes is convenient for places like libraries. A non admin account doesn't.